IRCTC and you have a waiting. As per the norms the online waiting e-ticket is considered without ticket and that is why you get your money returned in your bank account within a week in most cases. The waiting ticket from reservation counter can be used for travelling but you will not get a seat (depends on your co-passengers, if they are kind enough they may share their seat with you but most probably in long distances people don’t want to share).
Coming to the point of your waiting ticket being confirmed or not. The bitter truth is that you can only assume that your ticket gonna confirm and you will get a seat. The first that you should see before assuming is that how many passengers travel with that train within that destination. That means you have to estimate the rush, the amount of people travel with that train.
The second thing you should check is the season you are travelling in or the month or the day of the week you are travelling. Ask yourself some questions, like, is this a month of festival? Have you booked a ticket in summer or winter vacation? Or you have a waiting ticket for Saturday or Friday? If your answer is yes, then there is a slightly less chance of getting your ticket conformed. This is because lot of people travel to their homes in festivals. Students go to their homes and families go for Holidays and picnics in vacations. Many employees travel to their homes at the end of the week.
The third thing is the behaviour of waiting tickets being cleared. In many train like Shatabdi the waiting is cleared at the last moment. So if you are frequent traveller you may know about it, if you are not ask someone who knows about the train. You can also go to the railway enquiry and ask them that you have waiting in blah blah train, do you have some hint that the ticket will be confirmed or not?
So either you are travelling form Howrah Jn., New Delhi, Kanpur Central, Kalyan Jn., Chennai or from Patna you must check the above three points and then make an assumption that your ticket will be confirmed or not.